c/c++--conversion of hexadecimal type strings

In actual work, the conversion of strings and other data types is very common, there are many library functions, such as atoi , strtol ,sscanf , and so on, these functions online has a lot of information,

What I often use is that hexadecimal values are transmitted as strings and then parsed, and here's what I'm doing here:

Converts a 2-byte hexadecimal string into a short int with 2 bytes of shaping data:

Writing is not easy, reproduced please specify the source: http://blog.csdn.net/jscese/article/details/39054969

Short int xstrtoshortint (char *str) {       //int len=strlen (str);    short int ivalue = 0;   This translates to 2 bytes of shaped number    if ((LEN/2) >sizeof (ivalue))    {        printf ("Left overflow \ n");//Will overflow    }    int Ioffset = 0;  Shift    char *ptr;//character pointer    ptr = str;//start from scratch while    (*ptr! = ')  //To the last string Terminator    {        Ivalue = Ivalue << Ioffset; The first time does not shift, after each shift left 4bit, hexadecimal one character represents 4bit        if ((*ptr <= ' 9 ' && *ptr >= ' 0 '))        {            ivalue = ivalue + (*p TR-' 0 ');        }        else if ((*ptr >= ' a ' && *ptr <= ' F '))        {            ivalue = ivalue + (*ptr-' a ') +;        }        else if ((*ptr >= ' a ' && *ptr <= ' F '))        {            ivalue = ivalue + (*ptr-' a ') +;        }   To ivalue low 4bit assignment value        ptr++;        Ioffset = 4;    }    return ivalue;}

You can also do this, the principle is the same, just another way:

Short int xstrtoshortint (char *str) {    int len = strlen (str);    short int ivalue = 0;    for (int i = 0; i < len; i++)    {        if ((Str[i] <= ' 9 ' && str[i] >= ' 0 '))        {            Ivalue = Ivalue * + (Str[i]-' 0 ');  16 binary convertible Other binary        }        else if ((Str[i] >= ' A ' && str[i] <= ' F '))        {            Ivalue = Ivalue * + (Str[i] -' a ') + Ten;        }        else if ((Str[i] >= ' A ' && str[i] <= ' F ')        {            Ivalue = Ivalue * + + (Str[i]-' a ') +;        }    }    return ivalue;}

For example, call Xstrtoshortint ("1a4e"), you can get a 0x1a4e short int data, if you want to go to other data types, the principle is similar!

Thesprintf function is most commonly used when you turn a string.

c/c++--conversion of hexadecimal type strings